losing the house will also result in probably impeachment and tons of subpoena's and democrat ran investigations

Representatives can only recommend impeachment to the Senate, who then hold the trials and vote to oust. If the Democrats don't take the whole thing they're not getting rid of Trump.

You're supposed to have actual proof of actual criminal behavior when you impeach a president, not just really not liking him for being a meany, combined with an overblown conspiracy theory about Russia, but that's a detail the Democrats are clearly not going to be hung up.

Actually, the criterion for impeachment is not necessarily clear. Elected officials can be impeached for treason, bribery or any high crime or misdemeanour but what constitutes a 'high crime' is vague. According to Gerald Ford, when he was minority leader, a high crime is whatever the House of Representatives at the moment decides it is.

In theory they could impeach Trump over nothing but in practice such an impeachment is unlikely to stand up under trial, especially if Democrats don't get the numbers they want in the Senate. The reason Bill Clinton didn't get removed from office is that, even if Republican dissenters hadn't dissented, the Republicans just didn't have the numbers.